I’m getting ready to have a baby, and want to know what a placenta actually looks like. I have seen diagrams, but those don’t seem to look like anything recognizable. I really want my husband to be prepared before I deliver — I don’t need him passing out or anything.

Answer

A “temporary organ”

Ah, the placenta. It’s a strange thing, for sure: essentially an internal organ we make in adulthood, and then get rid of right after the baby’s born. (It’s also often referred to as the “afterbirth.”)

It is a pretty amazing thing, actually. It’s created alongside the embryo — out of the same genetic material as the baby, in fact — and its sole purpose is to act as baby’s life support system. It attaches to mom’s uterine wall on one side, and from the other side, the umbilical cord emerges and connects to the baby. The amniotic sac also grows from the placenta around the baby.

Mom’s experience of placenta

By the time your baby is full-term, the placenta will weigh about two pounds. If you have a vaginal birth, you will need to push just a little to deliver the placenta — this will usually be anywhere from about 5 to 30 minutes after your baby is born. (If you deliver via cesarean section, the doctors will remove the placenta from the uterus manually.) Usually by the time the placenta comes along, though, you will be so busy with your baby that it will probably feel like no more than a painless little gush.

So, yes, what does the placenta look like? As you’d probably expect, the thing is bloody. And big. And blobby. And depending on your life experiences, may look like a cow’s heart or some sort of tumor or like a bonanza of raw liver. But don’t be too freaked out — just remember that this thing allowed your baby to exist. (While we do advocate appreciation for the biology at work here, we’re not going to suggest that you eat the placenta after birth… but some people do.)

See a placenta

But a description of the thing can only go so far. The best way to get prepared is to really see one.

So, now that we’ve written enough to bump the photos down the page a bit so as not to offend any squeamish folks who accidentally clicked on this page, here’s a placenta I made earlier:

Here’s the side of the placenta that faced the baby,and part of the amniotic membrane

This is the side of the placenta that attached to the uterine wall

More placenta fun facts

All mammalian females — including the Blue Whale (average weight of over 200,000 pounds), the Etruscan Shrew (which weighs just about 2 grams on average) and, of course, humans — form placentas when they conceive.

In 2008, Researchers at the Stanford University School of Medicine reported that the placenta develops in two stages. “In the first stage, which runs from the beginning of pregnancy through mid-gestation, the placental cells primarily activate genes that mammals have in common with birds and reptiles… In the second stage, cells of the mammalian placenta switch to a new wave of species-specific genes. Mice activate newly evolved mouse genes, and humans activate human genes.”